1. Field of the Invention:
This invention relates to an iron golf club head made of a fiber-reinforced resin as its principal material, and more particularly, to an iron golf club head which can easily make centroid adjustment without changing the design of the outer shape of the club head.
2. Description of the Prior Art:
An iron golf club head made of a fiber-reinforced resin as its principal material in place of an iron golf club head made completely of a metal has been proposed as disclosed in Japanese patent application Kokai publication No. 61-249484 and in Japanese utility model application Kokai publication No. 61-154968. This iron golf club head made of the fiber-reinforced resin consists substantially of the fiber-reinforced resin or the like as its principal material except that its sole and hose are molded integrally from a metal.
Centroid adjustment is extremely important in a golf club head. If the centroid of the golf club head is moved to a lower position, for example, the fly-out angle of the hit ball can be increased and if it is moved to a rear part of the head, the sweet area can be enlarged. Conventionally, such centroid adjustment has been made by mixing metal particles in the fiber-reinforced resin or fitting a metallic plate to the back of the ball hitting face or increasing the width or thickness of the sole. However, centroid adjustment by such means involves the problem that its control is extremely difficult. In the case of a middle iron club or short iron club, there is also the problem that the centroid is likely to become higher because the weight distribution is not smooth and uniform and the design of a toe-heel balance for enlarging the sweet area is difficult. In the case of increasing the width and thickness of the sole, another problem is posed that the shape of the club head must be changed in addition to the problem described above.